Selective filtration of NMR signals arising from weakly- and strongly-coupled spin systems

• Published in: Journal of magnetic resonance (1997) 2023-09, Vol.354, p.107529-107529, Article 107529
• Main Authors: Lu, Jiaqi, Jerschow, Alexej, Korenchan, David E.
• Format: Article
• Language: English
• Subjects: NAD; NMR spectroscopy; Singlet order; Spectral editing
• ISSN: 1090-7807; 1096-0856
• DOI: 10.1016/j.jmr.2023.107529

Nuclear magnetic resonance (NMR) spectroscopy is a powerful technique for analyzing chemical and biological systems. However, in complex solutions with similar molecular components, NMR signals can overlap, making it challenging to distinguish and quantify individual species. In this paper, we introduce new spectral editing sequences that exploit the differences in nuclear spin interactions (J-couplings) between weakly- and strongly-coupled two-spin systems. These sequences selectively attenuate or nullify undesired spin magnetization while they preserve the desired signals, resulting in simplified NMR spectra and potentially facilitating single-species imaging applications. We demonstrate the effectiveness of our approach using a 31P spectral filtration method on a model system of nicotinamide dinucleotide (NAD), which exists in oxidized (NAD+) and reduced (NADH) forms. The presented sequences are robust to field inhomogeneity, do not require additional sub-spectra, and retain a significant portion of the original signal. [Display omitted] Overlapping signals often hinder NMR-based species identification. We introduce spectral editing sequences exploiting nuclear spin interactions in weakly- and strongly-coupled systems. These sequences suppress unwanted magnetization while preserving desired signals. Using a 31P filtration method on NAD+ and NADH molecular systems, we show it to be a robust selection method. •Spectral editing sequence inspired by singlet-to-triplet transfer elements.•The editing method is robust against inhomogeneity and could be used for imaging.•J-synchronized echo train removes strongly coupled resonances for precise editing.•Editing sequences separate overlapping NAD+ and NADH signals.•Robust editing sequences resistant to shim and pulse offset frequency variations.